French patent application No. 87/15739, filed Nov. 13, 1987 in the name of Alcatel CIT describes IC card readers in general, and an IC card contact frame in particular. It is specified therein that such a reader comprises card guiding or positioning means, optional means for verifying that a card is indeed present in the reader in a suitable position for reading, and contact elements which make electrical contact with conducting tabs on the IC card, whereby electrical circuits are set up with the apparatus including the IC card reader. The contact frame is a single part enabling the above-specified functions to be performed. Given manufacturing tolerances, it makes it possible, when an IC card is inserted, to ensure that the contact elements bend in such a manner as to ensure that the required contact pressure is always obtained.
Such a design suffers from the drawbacks that the contact elements apply the specified contact pressure from the beginning of card insertion, prior to the card being in the reading position. This gives rise to pointlessly high friction between these contact elements and the card, thus causing excessive wear. Because of this state of affairs, the desired contact pressure is as low as possible while still obtaining adequate electrical contact performance. In addition, and as mentioned in said prior patent application, the pressure of the contact elements is also used for holding the card in the reader against the return force of an end-of-stroke contact, for example. Insofar as the contact element pressure is limited, it follows that the pressure of the end-of-stroke contact is also limited.
These various considerations means that it is desirable for the contact pressure between the contact elements of the IC card reader and the contact tabs on the IC card to be established, at least in part, by mechanical means which act to set up electrical circuits with the IC card, once the card is substantially in the reading position.
The object of the present invention is to provide an IC card reader including such means.